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 * Copyright © 2002 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * California 95054, U.S.A. All rights reserved.  Sun Microsystems, Inc. has
 * intellectual property rights relating to technology embodied in the product
 * that is described in this document. In particular, and without limitation,
 * these intellectual property rights may include one or more of the U.S.
 * patents listed at http://www.sun.com/patents and one or more additional
 * patents or pending patent applications in the U.S. and in other countries.
 * U.S. Government Rights - Commercial software. Government users are subject
 * to the Sun Microsystems, Inc. standard license agreement and applicable
 * provisions of the FAR and its supplements.  Use is subject to license terms.
 * Sun,  Sun Microsystems,  the Sun logo and  Java are trademarks or registered
 * trademarks of Sun Microsystems, Inc. in the U.S. and other countries.  This
 * product is covered and controlled by U.S. Export Control laws and may be
 * subject to the export or import laws in other countries.  Nuclear, missile,
 * chemical biological weapons or nuclear maritime end uses or end users,
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 */

package org.javacc.parser;

/**
 * Describes expansions - entities that may occur on the right hand sides of
 * productions. This is the base class of a bunch of other more specific
 * classes.
 */

public class Expansion {

	/**
	 * The line and column number of the construct that corresponds most closely
	 * to this node.
	 */
	int line, column;

	/**
	 * A reimplementing of Object.hashCode() to be deterministic. This uses the
	 * line and column fields to generate an arbitrary number - we assume that
	 * this method is called only after line and column are set to their actual
	 * values.
	 */
	public int hashCode() {
		return line + column;
	}

	/**
	 * An internal name for this expansion. This is used to generate parser
	 * routines.
	 */
	String internal_name = "";

	/**
	 * The parser routines are generated in three phases. The generation of the
	 * second and third phase are on demand only, and the third phase can be
	 * recursive. This variable is used to keep track of the expansions for
	 * which phase 3 generations have been already added to a list so that the
	 * recursion can be terminated.
	 */
	boolean phase3done = false;

	/**
	 * The parent of this expansion node. In case this is the top level
	 * expansion of the production it is a reference to the production node
	 * otherwise it is a reference to another Expansion node. In case this is
	 * the top level of a lookahead expansion,then the parent is null.
	 */
	public Object parent;

	/**
	 * The ordinal of this node with respect to its parent.
	 */
	int ordinal;

	/**
	 * To avoid right-recursive loops when calculating follow sets, we use a
	 * generation number which indicates if this expansion was visited by
	 * LookaheadWalk.genFollowSet in the same generation. New generations are
	 * obtained by incrementing the static counter below, and the current
	 * generation is stored in the non-static variable below.
	 */
	public static long nextGenerationIndex = 1;

	public long myGeneration = 0;

	/**
	 * This flag is used for bookkeeping by the minimumSize method in class
	 * ParseEngine.
	 */
	public boolean inMinimumSize = false;

	public static void reInit() {
		nextGenerationIndex = 1;
	}

}
